When subjected to even only relatively warm temperatures (i.e. in hot weather) chocolate products—whether in the form of bars, tablets, coatings or other—tend to loose their desired character and shape, to become soft, unsatisfactory and sticky to handle and to loose their gloss (due to leaching of their fat constituents and to both the fats and sugars recrystallising at the surface—known as “blooming”). In particular, if wrapped, the chocolate product will adhere to its packaging and its surface will be marred when the wrapper is removed.
In its simplest form, chocolate is produced by grinding a mixture of cocoa liquor, sugar and milk solids (in the case of milk chocolate) to a desired degree of fineness before incorporating a certain amount of cocoa butter. The mixture is then placed in a so-called conching machine (or conge-mixer) in which it is agitated or “worked”, providing aeration that allows certain undesired aromas to escape and helping the final chocolate flavour to develop. During this step, also referred to as “finishing”, the sugar and milk solids become completely coated with fat. The resulting paste is finally tempered and either formed into a product for sale or stored for subsequent use.
Cocoa butter is responsible for some of the most important properties of the chocolate product. These properties include its sensory qualities (mouth feel and snap, for instance), its physical behaviour (hardness and shape retention) and its tendency to bloom. Bloom behaviour, in particular, is difficult to predict since its specific causes and mechanisms still remain largely unknown.
Conventional chocolate products tend to soften and melt between 30° C. and 35° C.—or even at lower temperatures depending on the nature and amount of cocoa butter used in the final composition.
Various processes have been proposed in order to provide chocolate products with higher temperature stability. These include:                replacing some or all of the cocoa butter with fats from non-cocoa sources which have higher melting points (e.g. cocoa butter improvers, cocoa butter replacers, cocoa butter substitutes and cocoa butter equivalents), and        adding a non-fat based structuring additive (or framing structure) to the chocolate composition.        
Unfortunately, the resulting products very often have an unpleasant taste, a less smooth mouth-feel and a perceptibly coarser and more brittle texture in comparison to conventional chocolate products (cf. EP-A-0 393 327, EP-A-0 637 420). Commercially, there is also a disincentive to using “additives” which have to be listed in the ingredients (as is the case, for example, for some cocoa butter replacers). There is therefore a clear need in the art for improved chocolate products which are comparable, from a sensory point of view, to high quality chocolate and which have improved heat and bloom resistance.